1. Field of the Invention
This invention relates to high-density power supply cabinets and particularly to high-density power supply cabinets with integrated remote monitoring capabilities.
2. Description of the Prior Art
Over its existence, the physical size of electronic equipment (such as computer servers and storage) has shrunk, its capabilities have increased, and its power density has dramatically increased. At the same time, most sophisticated electronic equipment remains dependent on a continuous supply of clean electrical power. These two demands (continuity and quality) have traditionally been met with two different capabilities—backup power supplies and uninterruptible power supplies. Traditionally, the backup power supply need has been met by using some kind of electromechanical source, such as Diesel-fired or natural-gas-fired generators. While these sources can provide backup power, it is usually very uneconomical to use these same sources for ensuring power quality and continuity—that task has traditionally fallen to uninterruptible power supplies (UPSs). Any reasonable design for a UPS will include all circuitry needed for power conditioning as well as for temporary power provisioning. UPSs can exist at the equipment level, at the rack level, or at the building or facility level.
Building-level UPSs have proven to be an effective and efficient solution to the power quality and continuity problems, but must usually be designed into the building at construction; after building construction is completed, adding a building-level UPS is extraordinarily expensive. Equipment-level UPSs can be effective in an office or home environment, but are quite inefficient when used for dense, rack-mounted equipment. Equipment-level UPSs take up a lot of valuable rack space, and are difficult to manage and control. A near-optimal solution seems to be UPSs that provide power to an entire rack.
Most modern electronic-equipment racks provide about 42 Rack Units (RUs) of space for installing equipment. Enough traditional, rack-mounted UPSs to supply a sufficient amount of power would take up more space in the rack that is practical.
As modern rack-mounted electronic equipment has become smaller and more powerful, it has thereby increased the demands for more power in a smaller space. Ignoring the need for uninterruptible power, a modern electronics rack could house 36 servers, each of which could have two power cables (one each for two redundant power supplies internal to the equipment), two network cables (one each for two redundant connections from two network interfaces to two network switches), and up to three cables for server control (either “KVM” (keyboard, video, and mouse) or “ILO” (Integrated Lights Out)). That adds up to as many as 252 cables in a space 19″ wide and 74.5″ high. The result is a tangle of cables at the back of the rack that looks like a “nest of snakes”. To hold all this cabling, many manufacturers have made available “wide cabinets,” as commercial off the shelf (COTS) products. These cabinets are about ten inches wider than standard racks to allow for cabling and cooling.